Metal and composite leading edge assemblies

ABSTRACT

Various components and methods related to a leading edge assembly are disclosed. The leading edge assembly can include an outer strike shell and a foam core. The foam core can be located inside the outer strike shell. The leading edge assembly can include a heating element with a plurality of sensors and wires. A method of manufacturing a leading edge assembly can include forming a composite layer, applying a metallic layer to the composite layer, installing an electronic device, and inserting a foam core into a cavity bounded by the composite layer and/or the electronic device.

This application is a divisional of U.S. patent application Ser. No.14/929,058, filed Oct. 30, 2015 the entire disclosure which is herebyincorporated by reference in its entirety.

BACKGROUND Field

This disclosure relates to protective covers for leading edge structuresin airflows, such as covers for the leading edges of noise attenuationdevices of auxiliary power units.

Certain Related Art

An auxiliary power unit (“APU”) can provide power to a vehicle, such asan aircraft, ship, or large land vehicle (e.g., large truck). The powerfrom the APU can be used to power various functions, such as temperaturecontrol systems, on-board computers, and otherwise. During operation,the APU can ingest air through an air inlet and route the air to amotor, which produces the power. The APU can generate significant noise,which can propagate through an inlet air assembly and disturb passengerson the vehicle (e.g., aircraft) and/or the surrounding environment(e.g., when the aircraft is on the ground). Accordingly, some APUs airinlets incorporate a noise attenuation device, such as one or moreacoustic splitters. The acoustic splitters divide the large throat ofthe overall air inlet into multiple smaller throats, which can reducenoise.

SUMMARY OF CERTAIN FEATURES

In some situations, the air being ingested to the APU can increase thelikelihood of damage to the leading edge (e.g., the foremost edge) ofthe acoustic splitters. For example, the leading edge of the splitterscan be subjected to high-speed foreign object debris (“FOD”) strikes.FOD strikes can damage the leading edge, which can result in ingestionof portions of the leading edge or inlet into the motor. Also, ice canform on the leading edge, which can impede or even close off the airinlet, which in turn can cause the motor to shutdown, operate lessefficiently, or even incur damage. Further, ice can also break off andfoul the motor. Another concern is rain erosion, which can beexacerbated by flight velocity. Rain erosion can be particularlyproblematic in non-metallic substances (e.g., composites), where thehydraulic action can wear through the substances in a short period,resulting in damage to the leading edge.

To protect the acoustic splitters from one or more of theabove-described problems, or other problems, the leading edge of theacoustic splitter can be provided with a protective shield, called aleading edge assembly (also called a leading edge cover). Thisdisclosure describes various systems, apparatuses, and methods relatedto leading edge assemblies. In some embodiments, the leading edgeassemblies comprise an outer strike shell. The outer strike shell caninclude a metallic layer and a composite layer. In some embodiments, themetallic layer is external to the composite layer, which can allow themetallic layer to protect the composite layer against FOD damage, rainerosion, or other damage, and can allow the composite layer to providestrength to the metallic layer.

In some embodiments, the leading edge assembly comprises a core. Theouter strike shell can mate with the core, which can allow the outerstrike shell to protect the core from FOD damage, rain erosion, or otherdamage, and can allow the core to support the outer strike shell. Thecore can be made of a foam material, such as a rigid fire-retardantfoam.

Some embodiments include one or more heating elements. The heatingelements can transfer heat to the outer strike shell, which can reducethe chance of ice formation. The heating elements can be embedded intothe leading edge assembly. In some embodiments, the heating elements areconfigured to provide substantially even heating across to the outersurface of the outer strike shell. In some examples, the protectivecover is manufactured by forming each of the layers of the protectivecover onto each other to reduce the assembly. Some embodiments includeother electric components, such as sensors.

BRIEF DESCRIPTION OF THE FIGURES

Various embodiments are depicted in the accompanying drawings forillustrative purposes, and should not be interpreted as limiting thescope of the embodiments. Furthermore, various features of differentdisclosed embodiments can be combined to form additional embodiments,which are part of this disclosure.

FIG. 1 illustrates a side perspective view of an embodiment of a coverfor a noise attenuation device.

FIG. 2 illustrates a front perspective view of an embodiment of a coverfor a noise attenuation device.

FIG. 3 illustrates a perspective cross-sectional view of an embodimentof a cover for a noise attenuation device.

FIGS. 3A-3C illustrate various alternative layer configurations of aportion of the cover of FIG. 3.

FIG. 4 illustrates a perspective view of an embodiment of a master plugused in the assembly and manufacturing of a cover for a noiseattenuation device.

FIG. 5 illustrates a perspective view of an embodiment of an outerstrike shell mold used in the assembly and manufacturing of a cover fora noise attenuation device.

FIG. 6 illustrates a perspective view of an embodiment of a foam coremold used in the assembly and manufacturing of a cover for a noiseattenuation device.

FIG. 7 illustrates a perspective view of an embodiment of an outerstrike shell of the cover for a noise attenuation device.

FIG. 8 illustrates a perspective view of an embodiment of an assembledcover for a noise attenuation device.

FIG. 9 schematically illustrates an embodiment of a method formanufacturing a leading edge cover.

FIG. 10 schematically illustrates another embodiment of a method formanufacturing a leading edge cover.

DETAILED DESCRIPTION OF CERTAIN EMBODIMENTS

Various leading edge assembly covers, assemblies, and manufacturingmethods are disclosed to illustrate various examples that may beemployed to achieve one or more desired improvements. For purposes ofpresentation, certain embodiments are disclosed with respect to a noiseattenuation device, but the disclosed invention can be used in othercontexts as well. Indeed, the described embodiments are examples onlyand are not intended to restrict the general disclosure presented andthe various aspects and features of this disclosure. The generalprinciples described herein may be applied to embodiments andapplications other than those discussed herein without departing fromthe spirit and scope of the disclosure. This disclosure should beaccorded the widest scope consistent with the principles and featuresthat are disclosed or suggested herein.

Although certain aspects, advantages, and features are described herein,it is not necessary that any particular embodiment include or achieveany or all of those aspects, advantages, and features. For example, someembodiments may not achieve the advantages described herein, but mayachieve other advantages instead. No feature, component, or step isnecessary or critical.

Overview

In some embodiments, a leading edge assembly can include an outer strikeshell and a core, such as a foam core. The outer strike shell can have ametallic skin and a composite layer. In some embodiments, the metallicskin can be applied (e.g., plated or otherwise applied, such as with anelectroless or electrolytic process) to the exterior of composite layer.This can result in a metallic primary layer for rain erosion and FODstrike protection. In some examples, the metallic layer can form asurface thermal mass. The surface thermal mass can spread the heatoutput substantially evenly across the leading edge surface. In someembodiments, the leading edge assembly can include an embedded heaterand/or sensor.

In many respects, forming the primary cover (e.g., the outermost surfaceof the leading edge assembly) from a metal can provide certainadvantages. For example, a metal primary cover can provide significantresistance to impact damage, such as due to FOD strikes. Also, metalcovers can provide better heat transfer (e.g., the ability of heat tospread across the leading edge) when compared to composites, which havelittle heat spread across the surface and thus can make ice formationmore likely. However, metal covers can be expensive to form as they mayinvolve matched tooling, and/or a secondary structure to attach theleading edge to the splitter. The metal cover may need to be mated witha heater, which can result in cold spots, less than full heat coverageon the surface, and/or additional weight. Furthermore, manufacturing(e.g., forming and assembling) a metal cover can tend to distort themetal, which can result in an uneven surface area with thick and thinareas, where the thin areas can have the highest loading. The metalcover may need secondary structures (e.g., brackets or otherwise) to beadded so that the cover can be mounted to the noise attenuation device.

Composites, on the other hand, can be relatively easy to manufacture andform and typically with less expensive tooling. Mounting structures(which can be metals or non-metals) can be bonded into a compositecover. This can avoid the need to add secondary mounting structureand/or to pierce the leading edge with rivets or fasteners, which canweaken the unit. Disadvantages of using composites can include damagefrom rain erosion. Although such rain erosion damage can be mitigatedthrough frequent and repeated applications of rain-protective finishes,this is inconvenient and costly. Rain-protective finishes can suppressthermal transmission, resulting in higher power requirements and areduction in ice deterrence. Rain-protective finishes can also limitheat spreading such that only areas substantially directly over theheater element itself are warmed. In some examples, the lateral spreadof heat in composites can result in only 60% of the surface area of theleading edge being heated.

In some examples, the leading edge assembly can be replaceable. This canbe convenient because the leading edge assembly may be life-limited,such as due to the environmental factors described above, and the entireair inlet can be expensive to scrap. Due to aerodynamic or acousticconcerns, the outer periphery of the inlet covers can often be comprisedof complex compound curves. Therefore, a way to positively locate theacoustic splitter covers on such complex shapes can be beneficial. Insome examples, acoustic splitters can be non-symmetrical in shape (e.g.,about a longitudinal axis). In some embodiments, several (e.g., 2, 3, 4,5, 6, 7, or more) leading edge assemblies, each with distinct shapes,may be used for a single air inlet and/or on a single acoustic splitter.

Certain Embodiments of a Leading Edge Assembly

As mentioned above, the leading edge assembly can include an outerstrike shell and a core. The outer strike shell can have a compositelayer that is external to the core. The outer strike shell can have ametallic skin (also called a metallic layer) that is external to thecomposite layer. For example, the metallic layer can be deposited ontothe composite layer. In various embodiments, the leading edge assemblycomprises a noise attenuation device cover.

The leading edge assembly can include a core (also called an interior)that can be formed from a foam, such as a rigid, closed cell, and/orfire retardant foam. In some embodiments, the foam can contain detailsto locate the leading edge cover assembly in place. In some examples,the foam can thermally insulate and/or isolate the heater, therebydirecting thermal energy towards the metallic skin. As will be discussedin more detail below, the foam can add support and/or rigidity to thethin outer strike shell. In some embodiments, the foam forms a part of amulti-layer (e.g., sandwich panel type) construction of the leading edgeassembly. In some embodiments, the foam can completely or substantiallycompletely bond with the outer strike shell such that little or no postassembly or bonding processes are subsequently used.

FIGS. 1-2 illustrate example embodiments of leading edge covers. Thesurface and/or shape of the leading edge assembly (e.g., a noiseattenuation device cover) can vary. Several different leading edgeassemblies can be combined (e.g., lined up end to end) to provideprotection along the length of an acoustic splitter. FIGS. 1-2illustrate two examples of leading edge covers that fit different typesof surfaces of a leading edge assembly. The leading edge cover can comein any variety of sizes and shapes.

FIG. 1 illustrates a side view of an embodiment of a leading edge cover100, such as a leading edge cover that can be configured for an acousticsplitter. In some examples, the leading edge cover 100 can include anouter strike shell 105, which can include an inner composite layer 120and an outer metallic layer 122. As shown, the outer strike shell 105can be curved and can have an apex at a forward end 150 (e.g., the endof the shell 105 that will be facing into the wind when installed on anacoustic splitter). Internal to the outer strike shell 105, the leadingedge cover 100 can include a core 110, such as a foam core. The core 110can include a rear surface 160 and a channel 115. In some examples, thechannel 115 can be configured to fit over the leading edge surface of anoise attenuation device, such as an acoustic splitter. For example, thechannel 115 can be configured to receive a correspondingly shapedportion of the noise attenuation device.

FIG. 2 illustrates a front view of another embodiment of a leading edgecover 100A. As with the leading edge cover 100, the leading edge cover100A can include an outer strike shell 105A and a core 110A with achannel 115A.

FIG. 3 illustrates an example of a layered configuration of the leadingedge cover 100. For example, as shown, the core 110 can be sandwichedbetween the upper and lower portions of the outer strike shell 105. Insome embodiments, the outer strike shell 105 bounds upper, lower, andforward edges of the core 110.

As shown, the outer strike shell 105 can form the outer surface of theleading edge cover 100. In some embodiments, the outer strike shell 105can include a composite layer 120. The composite layer 120 can belocated along the inner surface of the outer strike shell 105. In someembodiments, a core 110 can be located between the outer strike shell105. The leading edge cover 100 can include a heating element 125 andsensors and lead wires 130 that are located between the various layersof the leading edge cover 100.

The composite layer 120 can be formed of a various composites. Forexample, the composite layer 120 can be manufactured from fiberreinforced thermosetting dielectric resins. The fiber layers andalignments can be configured to provide rigidity to match therequirements of the installation. In some examples, the composite layer120 does not include conductive fibers. This can reduce damage fromlightning strikes, which can cause damage to the electrical componentshoused within the outer strike shell 105. The thickness of the compositelayer 120 can be determined by the dielectric withstand voltagerequirement. For example, a thinner outer layer may provide better heattransfer, while a thicker outer layer may provide better insulation forthe electrical components housed within the outer strike shell 105. Thiscan reduce damage by lightning strikes or protect individuals (e.g.,technicians) from electrical shock. In some embodiments, the compositelayer 120 comprises 1, 2, 3, 4, 5, 6, or more layers of compositematerial.

As discussed above, the leading edge cover 100 can include an outerstrike shell 105 with a metallic layer 122. In some embodiments, themetallic layer 122 comprises nickel. In some embodiments, the metalliclayer 122 can be formed from copper. In some embodiments, the metalliclayer 122 comprises hard chrome. In certain embodiments, the metalliclayer 122 comprises a combination of metals, such as copper and nickel,copper and hard chrome, or other combinations. In some embodiments, themetallic layer 122 can be deposited with an electroless or electrolyticprocess.

In some embodiments, the metallic layer 122 is applied to the compositelayer 120. For example, vapor deposition can be used to treat thecomposite layer 120 with titanium, aluminum, nickel, copper, stainlesssteel, chrome, or other materials. As will be discussed in more detailbelow, these treatments can be applied over some or all of the completedcomposite layer 120. In some embodiments, after treatment, the outersurface of the outer strike shell 105 can have an appearance similar toa formed metal leading edge.

As discussed above, in some examples, the leading edge cover 100 can beconstructed to inhibit or prevent the formation of ice on the surface ofthe leading edge cover 100. In some embodiments, ice formation can bedeterred by including a heating element 125 in the leading edge cover100. In some examples, the heating element 125 can be laminated suchthat the outer and inner dielectric layers are part of the manufacturingprocess. This can ensure compatible thermal expansion characteristicsacross various environments, which can result in a longer life for theleading edge cover assembly 100.

The heating element 125 can be mounted in such a way as to facilitatetransferring heat to the composite layer 120 and/or the metallic layer122. As shown in the cross-sectional view of FIG. 3A, the heatingelement 125 can be spaced apart from the composite layer 120 by aportion of the core 110. In certain variants, as shown in FIG. 3B, theheating element 125 can be adjacent and/or abutted with the compositelayer 120. In some embodiments, such as is shown in FIG. 3C, the heatingelement 125 is embedded in the composite layer 120. In certainimplementations, the heating element 125 can be adjacent and/or abuttedwith the metallic layer 122, which can provide particularly efficienttransfer of heat to the metallic layer 122. In certain implementations,the heating element 125 can be bonded to the inside of the compositelayer 120. For example, the heating element 125 can be bonded to thecomposite layer 120 in certain embodiments in which the heating element125 is in an elastomer (e.g., silicone rubber) and/or embodiments inwhich the outer strike shell 105 comprises carbon fiber construction. Insome variants, the heating element 125 is positioned in a pocket in thecomposite layer 120.

The leading edge cover 100 can include various electric elements 130 tosupport the heater function. In some examples, the various electricelements 130 can include components such as lead wires, fuses, sensors,and thermostats. These components can be installed and tested prior toinstalling the core 110 within the outer strike shell 105. In someembodiments, the leading edge cover 100 includes one or more sensors(e.g., thermostats) adjacent to, or in, the outer strike shell 105. Forexample, the sensor or sensors can be positioned near or at the apex ofthe curved outer strike shell 105.

In some examples, the leading edge cover 100 does not include theheating element 125, such as for applications in which the leading edgeassembly will not be used in an environment in which ice formation is aconcern. In certain examples, the composite layer 120 (or at least aportion of it) can be formed from a non-reinforced thermoplastic (e.g.,polyether ether ketone (PEEK)) or fire retardant nylon. In someembodiments, the composite layer 120 is formed with a 3D Printer. Insome embodiments, not including the heating element 125 can allow theleading edge cover 100 to be produced at a lower cost, and/or can permitdifferent materials to be used, such as materials with lower physicalproperties (e.g., inexpensive materials or lower dielectric propertiescompared to the materials used in some embodiments with the heatingelement 125).

As indicated above, the leading edge cover 100 can include a core 110.In some embodiments, the core 110 can provide support for the outerstrike shell 105. The core 110 can form a mounting surface forattachment to the acoustic splitter assemblies. In some examples, thecore 110 can be formed from an expanding fire retardant foam. In someexamples, the core 110 can secure various internal elements (e.g., theheating elements 125, sensors, etc.). This can provide high resistanceto vibration and/or shock, which can reduce the chance of damage and/orfailure. In some examples, the core 110 can prevent fluid (e.g., water)intrusion. The foam properties can be modified to increase or decreaseflexibility, flex, or temperature performance as determined by usage orspecification. In some embodiments, the foam comprises a fire-retardantand/or self-skinning foam. For example, the foam can be StaFoam R/T™. Inseveral implementations, the foam comprises a two-component foam. Insome variants, the foam comprises a one-component foam. In certainembodiments, the foam comprises a heat curing syntactic epoxy foam.

As will be discussed below, in assembling the leading edge cover 100,the core 110 can be constrained by mold tools. In some examples, theprocess for assembling the core 110 can be envisioned to provide a fullyfinished assembly requiring little or no post processing prior tocompletion. For example, by filling the void between a mountinginterface surface and an outer composite shell, a sandwich-panel-typeassembly can be formed which provides sufficient torsional andstructural rigidity for a leading edge structure. In some embodiments,the mounting interface can include locating details, which are providedby the tooling design and/or can aid in locating one or more portions ofa mold relative to the leading edge cover 100.

Certain Methods of Manufacturing a Leading Edge Assembly

In various embodiments, the leading edge cover 100 is iterativelybuilt-up during manufacturing. For example, the outer strike shell 105can be formed by forming the composite layer 120, and applying themetallic layer 122 to the composite layer 120 (e.g., on an outer surfaceof the composite layer 120). Electric components, such as heatingelements and/or sensors, can be installed in and/or or the outer strikeshell 105. The core 110 can be formed within the outer strike shell 105.For example, the core 110 can be inserted into the outer strike shell105, such as by being injected as a liquid and allowed to harden in theouter strike shell 105. This can provide a core with a shape thatclosely corresponds to the internal shape of the outer strike shell 105as well as the electric components.

In some examples, the described manufacturing process can require littleto no post processing prior to completion. This can provide a number ofadvantages. For example, the described manufacturing process can providefast turn, low cost tooling and/or provide for low cost modifications.In some examples, the described manufacturing process can require nosecondary finishing operations, inside or out. As well, in someembodiments, the sandwich panel construction can provide good resistanceto FOD strikes. As well, in some examples, the construction of theleading edge cover 100 can provide a structure that can be groundablefor lightning strikes.

In manufacturing the leading edge cover 100, a master plug can begenerated. FIG. 4 illustrates an example of the master plug 200. Asshown, in some embodiments, the master plug 200 can resemble or beidentical to the overall shape of the completed leading edge cover 100.Like the leading edge cover 100, the master plug 200 can include acurved outer surface 240, a flat top surface 235, and a channel 245.

In some examples, the master plug 200 can be generated using 3Dprinting. In some examples, the master plug 200 can be created from anylon type material. To save costs, in some embodiments, the master plug200 can have a hollow interior, but with sufficient wall thickness towithstand tooling effort. In some examples, the thickness can be atleast 0.060 inches. Additional tooling indices, alignments, orseparators can be added to the master plug 200 prior to 3D printing.

In some examples, the master plug 200 can be used to form a plurality oftooling for forming the leading edge cover 100. For example, the masterplug 200 can be used as a positive piece from which a multi-piecenegative mold can be formed, such as the front and rear mold portionsdiscussed below. In order to withstand high temperatures, the initialmaster plug 200 can be made of a 3D plastic that can be ambient or lowtemperature cured. In some examples, the master plug 200 can be madefrom a plurality of components. The components can first be made of“FastCast” polyurethane. Each of the components can be reinforced with apermanent epoxy or polyester glass. In some examples, the master plug200 is not consumed during tooling and can therefore be reused.

FIGS. 5-6 illustrate an embodiment of a plurality of certain toolingcomponents. FIG. 5 illustrates an example of a front mold portion, suchas an outer strike shell mold 300. In some examples, the outer strikeshell mold 300 includes an inner curved surface 350. As will bedescribed below, the inner curved surface 350 can be used to form theouter strike shell 105. In some embodiments, the inner curved surface350 corresponds to the curved outer surface 240 of the master plug 200.

FIG. 6 illustrates an example of a rear mold portion, such as a coremold 400. In some embodiments, the core mold 400 can be used to formsome or all of the inner mounting interface of the leading edge cover100. The core mold 400 can include a surface 455. As will be discussedin more detail below, the surface 455 can form the rear surface 160 ofthe leading edge cover 100. The core mold 400 can include a fold orprojection 470. In some examples, the projection 470 can be used to formthe channel 115 of the leading edge cover 100. In some embodiments, theplug 200, outer strike shell mold 300, and/or the core mold 400 are madeof nickel. This can facilitate higher production rates and/or quality.In some examples, using nickel tools can allow quick heating and coolingof the material of the outer strike shell 105, which can provide for asmooth and metallic finish. In some embodiments, the core mold 400includes one or more ports 460.

In some examples, the outer strike shell mold 300 can be used to formthe outer strike shell 105. In some embodiments, the outer strike shell105 can be formed by laying up multiple layers of composite onto theinner curved surface 350 of the outer strike shell mold 300. In someexamples, the composite used can be a glass-reinforced resin. In otherexamples, the outer strike shell 105 can be formed using vacuum bag typeprocessing. In examples where heating is desired, the heating element125 can be built into the layers of the composite as the multiple layersare being laid up. In some examples, the outer strike shell 105 canbuilt-up to be at least about 0.03 inches thick.

After the outer strike shell 105 is formed, it can be cured and/ortrimmed to a desired size. In some embodiments, the metallic layer 122(e.g., nickel, copper, or otherwise) can be applied to the outer strikeshell 105. For example, the outer strike shell 105 can be coated using aplating process, such as electroless or electrolytic plating. In somevariants, the metallic layer 122 is applied with a vapor depositionprocess. In some embodiments, such as certain embodiments using anelectroless nickel application process, the deposition thickness is atleast about 0.0005 inches and/or less than or equal to about 0.0008inches. The application can be sufficient to support conventionalelectrolytic plating. In some embodiments, such as certain embodimentsusing an electrolytic nickel plating process, the thickness is at leastabout 0.002 inches and/or less than or equal to about 0.005 inches. Incertain implementations, the metallic layer 122 covers at least about90% of the surface area of a curved outer surface of the outer strikeshell 105. In some embodiments, the lead wires, sensors, fuses and/orother electronic components 130 can be installed and tested after themetallic layer 122 is applied to the outer strike shell 105. In somevariants, at least one lead wire, sensor, fuse, and/or other electroniccomponent can be installed and tested before the metallic layer 122 isapplied.

FIG. 7 illustrates an example of a formed outer strike shell 105. As wasdescribed above, the outer strike shell 105 can have an outside surface106. The outside surface 106 can comprise the metallic layer 122. Asshown, the outer strike shell 105 can include an inside surface 107 andan inner cavity 108. The outer strike shell 105 can have ends 109A,109B. As will be described in more detail below, in some embodiments,the inside surface 107 and inner cavity 108 can interface with the core110.

As described above, the leading edge cover 100 can be manufactured suchthat it produces a sandwiched configuration. In some examples, toproduce the sandwiched configuration, the completed outer strike shell105 can be placed back in the outer strike shell mold 300. This canresult in the outside surface 106 of the outer strike shell 105 beingadjacent and/or in contact with the inner curved surface 350 of theouter strike shell mold 300. In some embodiments, the core mold 400 canbe used to form a rear portion of the leading edge cover 100. Forexample, the core mold 400 can be prepped, located, and/or securedrelative to the outer strike shell 105 and/or the outer strike shellmold 300. In some examples, the core mold 400 can be positioned betweenthe ends 109A, 109B, within the inner cavity 108, and/or adjacent theinside surface 107 of the outer strike shell 105. In someimplementations, the projection 470 of the core mold 400 can extend intothe inner cavity 108.

In some examples, once the core mold 400 has been put into place, thematerial to form the core 110 can be mixed and introduced into the innercavity 108. For example, the core 110 can be injected as a liquidthrough the ports 460, which can be located on the top of the core mold400. The liquid core material can fill some or all of the space in theinner cavity 108. In some embodiments, the liquid core material cannotfill the space occupied by the projection 470, which can result in thatspace becoming the channel 115. In some examples, as discussed above,the core 110 can be composed of a two-component fire retardant material,such as fire retardant polyurethane. After injection of the corematerial, the core can be allowed to cure for a period. Some embodimentsinclude heating to facilitate the curing process.

After the core 110 has cured, the outer strike shell mold 300 and thecore mold 400 can be separated (e.g., pulled apart) from each other toreveal the leading edge cover 100. The leading edge cover 100 can thenbe prepared for final inspection and installation without any additionalprocessing required.

An example of the formed leading edge cover 100 is illustrated in FIG.8. As shown in FIG. 8, the leading edge cover 100 includes an outerstrike shell 105 and an inner core 110. The core 110 can further includean opening 165 and a channel 115 that can be formed by the projection470 of the core mold 400. As well, the core 110 can include a rearsurface 160 formed by the shape of the underside of the surface 455 ofthe core mold 400. For example, in the embodiments shown, the rearsurface 160 is generally flat.

The method of manufacturing a leading edge cover can include anycombination of the aforementioned steps. FIGS. 9-10 illustrate twoexample embodiments of methods for manufacturing a leading edge cover900, 1000. With regard to FIG. 9, as shown, in some embodiments, themethod 900 can include forming a composite layer 905. For example,layers of composite material can be built-up on the inside of the curvedmold. Some embodiments include applying a metal layer to the compositelayer 910. For example, the outer strike shell 105 can be coated usingan electroless or electrolytic plating process. Certain embodimentsinclude installing accessories (e.g., electronics, such as heatingelements, sensors, etc.) 915. For example, the accessories 915 can beinstalled into the inner surface of the outer strike shell 105. Somevariants include forming a core 920. For example, the core 920 can be afoam core that is injected as a liquid and allowed to harden in theouter strike shell 105.

The method of manufacturing 1000 can include any or all of the steps ofthe method 900. As shown in FIG. 10, in some embodiments, the method1000 can include forming a composite layer 1005. In some examples,layers of composite material can be build-up on the inside of the curvedmold. The composite layer 1005 can be removed from the base mold 1007.In some examples, the outer strike shell mold is not consumed in theforming of the composite layer 1005. A metal layer can be applied to thecomposite layer 1010. For example, the outer strike shell 105 can becoated using an electroless or electrolytic plating process. The methodof manufacture 1000 can then include inserting the composite layer intothe base mold 1013. For example, the base mold 1013 can retain thecomposite layer 1005 as the leading edge cover is assembled. The methodof manufacturing 1000 can include installing accessories 915 (e.g.,electronics, such as heating elements, sensors, etc.) into the innersurface of the composite layer 1015. For example, the accessories 915can be heating elements and/or sensors. The method of manufacture 1000can include adding a rear mold into the formed composite layer 1017. Forexample, the rear mold can be used to form some or all of the innermounting interface of the leading edge cover. The method can includeforming the core into the composite layer. For example, the method caninclude introducing the core material through one or more ports andallowing the core material to cure.

Certain Terminology

Terms of orientation used herein, such as “top,” “bottom,” “horizontal,”“vertical,” “longitudinal,” “lateral,” and “end” are used in the contextof the illustrated embodiment. However, the present disclosure shouldnot be limited to the illustrated orientation. Indeed, otherorientations are possible and are within the scope of this disclosure.Terms relating to circular shapes as used herein, such as diameter orradius, should be understood not to require perfect circular structures,but rather should be applied to any suitable structure with across-sectional region that can be measured from side-to-side. Termsrelating to shapes generally, such as “circular” or “cylindrical” or“semi-circular” or “semi-cylindrical” or any related or similar terms,are not required to conform strictly to the mathematical definitions ofcircles or cylinders or other structures, but can encompass structuresthat are reasonably close approximations.

Conditional language, such as “can,” “could,” “might,” or “may,” unlessspecifically stated otherwise, or otherwise understood within thecontext as used, is generally intended to convey that certainembodiments include or do not include, certain features, elements,and/or steps. Thus, such conditional language is not generally intendedto imply that features, elements, and/or steps are in any way requiredfor one or more embodiments.

Conjunctive language, such as the phrase “at least one of X, Y, and Z,”unless specifically stated otherwise, is otherwise understood with thecontext as used in general to convey that an item, term, etc. may beeither X, Y, or Z. Thus, such conjunctive language is not generallyintended to imply that certain embodiments require the presence of atleast one of X, at least one of Y, and at least one of Z.

The terms “approximately,” “about,” and “substantially” as used hereinrepresent an amount close to the stated amount that still performs adesired function or achieves a desired result. For example, in someembodiments, as the context may dictate, the terms “approximately”,“about”, and “substantially” may refer to an amount that is within lessthan or equal to 10% of the stated amount. The term “generally” as usedherein represents a value, amount, or characteristic that predominantlyincludes or tends toward a particular value, amount, or characteristic.As an example, in certain embodiments, as the context may dictate, theterm “generally parallel” can refer to something that departs fromexactly parallel by less than or equal to 20 degrees.

Unless otherwise explicitly stated, articles such as “a” or “an” shouldgenerally be interpreted to include one or more described items.Accordingly, phrases such as “a device configured to” are intended toinclude one or more recited devices. Such one or more recited devicescan also be collectively configured to carry out the stated recitations.For example, “a processor configured to carry out recitations A, B, andC” can include a first processor configured to carry out recitation Aworking in conjunction with a second processor configured to carry outrecitations B and C.

The terms “comprising,” “including,” “having,” and the like aresynonymous and are used inclusively, in an open-ended fashion, and donot exclude additional elements, features, acts, operations, and soforth. Likewise, the terms “some,” “certain,” and the like aresynonymous and are used in an open-ended fashion. Also, the term “or” isused in its inclusive sense (and not in its exclusive sense) so thatwhen used, for example, to connect a list of elements, the term “or”means one, some, or all of the elements in the list.

Overall, the language of the claims is to be interpreted broadly basedon the language employed in the claims. The language of the claims isnot to be limited to the non-exclusive embodiments and examples that areillustrated and described in this disclosure, or that are discussedduring the prosecution of the application.

SUMMARY

Although various covers have been disclosed in the context of certainembodiments and examples (e.g., noise attenuation devices), thisdisclosure extends beyond the specifically disclosed embodiments toother alternative embodiments and/or uses of the embodiments and certainmodifications and equivalents thereof. For example, any of the disclosedcovers can be used on the leading edge of other types of devices, suchas wings, vanes, blades, propellers, impellers, or otherwise. Variousfeatures and aspects of the disclosed embodiments can be combined withor substituted for one another in order to form varying modes of theconveyor. The scope of this disclosure should not be limited by theparticular disclosed embodiments described herein.

Certain features that are described in this disclosure in the context ofseparate implementations can also be implemented in combination in asingle implementation. Conversely, various features that are describedin the context of a single implementation can also be implemented inmultiple implementations separately or in any suitable subcombination.Although features may be described above as acting in certaincombinations, one or more features from a claimed combination can, insome cases, be excised from the combination, and the combination may beclaimed as any subcombination or variation of any subcombination.

Moreover, while operations may be depicted in the drawings or describedin the specification in a particular order, such operations need not beperformed in the particular order shown or in sequential order, and alloperations need not be performed, to achieve the desirable results.Other operations that are not depicted or described can be incorporatedin the example methods and processes. For example, one or moreadditional operations can be performed before, after, simultaneously, orbetween any of the described operations. Further, the operations may berearranged or reordered in other implementations. Also, the separationof various system components in the implementations described aboveshould not be understood as requiring such separation in allimplementations, and it should be understood that the describedcomponents and systems can generally be integrated together in a singleproduct or packaged into multiple products. Additionally, otherimplementations are within the scope of this disclosure.

Some embodiments have been described in connection with the accompanyingfigures. The figures are drawn and/or shown to scale, but such scaleshould not be limiting, since dimensions and proportions other than whatare shown are contemplated and are within the scope of the disclosedinvention. Distances, angles, etc. are merely illustrative and do notnecessarily bear an exact relationship to actual dimensions and layoutof the devices illustrated. Components can be added, removed, and/orrearranged. Further, the disclosure herein of any particular feature,aspect, method, property, characteristic, quality, attribute, element,or the like in connection with various embodiments can be used in allother embodiments set forth herein. Additionally, any methods describedherein may be practiced using any device suitable for performing therecited steps.

In summary, various embodiments and examples of leading edge assemblieshave been disclosed. Although the assemblies have been disclosed in thecontext of those embodiments and examples, this disclosure extendsbeyond the specifically disclosed embodiments to other alternativeembodiments and/or other uses of the embodiments, as well as to certainmodifications and equivalents thereof. This disclosure expresslycontemplates that various features and aspects of the disclosedembodiments can be combined with, or substituted for, one another. Thus,the scope of this disclosure should not be limited by the particulardisclosed embodiments described above, but should be determined only bya fair reading of the claims that follow.

The following is claimed:
 1. A method for manufacturing a leading edgeassembly, the method comprising: forming a composite layer; applying ametal layer to an exterior surface of the composite layer; installing anelectronic component to an interior surface of the composite layer;injecting a foam core material into a cavity bounded by the interiorsurface of the composite layer and/or the electronic component; forminga channel in the foam core material, the channel configured to engagewith a portion of an air inlet component; and curing the foam corematerial in the cavity.
 2. The method of manufacturing of claim 1,wherein forming the composite layer comprises laying-up multiple layersof a composite on a curved surface of a mold.
 3. The method ofmanufacturing of claim 2, wherein the composite comprises glassreinforced resin.
 4. The method of manufacturing of claim 2, whereinforming the composite layer further comprises applying a vacuum to thelayers of composite.
 5. The method of manufacturing of claim 1, whereinapplying the metal layer to the exterior surface of the composite layercomprises using vapor deposition to deposit a metal to the exteriorsurface of the composite layer.
 6. The method of manufacturing of claim1, wherein applying the metal layer to the exterior surface of thecomposite layer comprises plating the exterior surface of the compositelayer with a metal.
 7. The method of manufacturing of claim 6, whereinplating the exterior surface of the composite layer with a metalcomprises using electroless or electrolytic nickel plating.
 8. Themethod of manufacturing of claim 1, wherein installing the electroniccomponent to the composite layer comprises embedding a heating elementin the composite layer.
 9. The method of manufacturing of claim 1,further comprising forming a front mold and a rear mold from a masterplug, wherein the front mold includes a curved surface and the rear moldincludes a protrusion, the protrusion configured to form the channel.10. The method of manufacturing of claim 1, wherein injecting the foamcore material into the cavity bounded by the interior surface of thecomposite layer comprises injecting the foam core material as a liquidinto the cavity via a port in a rear mold structure.
 11. The method ofmanufacturing of claim 1, further comprising installing the compositelayer in an outer mold before injecting the foam core material.